Device for cleaning a functional surface for guiding or treating a material web

ABSTRACT

The disclosure relates to a device for cleaning a functional surface for guiding or treating a material web, preferably a non-woven wed. The device includes a pivotably mounted roller body, a plurality of hollow cylindrical brush segments being disposed on the circumference thereof and positively connected to each other and tensioned between two adjusting rings disposed at the circumference of the roller body. According to various embodiments, in order to ensure secure tensioning of the brush segments regardless of the surrounding conditions, at least one of the adjusting rings is axially flexibly retained at the circumference of the roller body and a compression ring rotationally fixed to the flexible adjusting rings is axially tensioned against the roller body by means of at least one spring element, such that an axial force acting on the brush segments is generated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of PCT International PatentApplication No. PCT/EP2010/061400 filed on Aug. 5, 2010, entitled“DEVICE FOR CLEANING A FUNCTIONAL SURFACE FOR GUIDING OR TREATING AMATERIAL WEB,” which claims priority to German Patent Application No. 102009 037 126.5 filed on Aug. 11, 2009, the contents and teachings ofeach of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The invention relates to a device for cleaning a functional surface forguiding or treating a material web.

BACKGROUND

In the manufacture of fibrous nonwoven webs, in particular in an airlaidprocess in which a plurality of fiber pieces are shaped on a laydownbelt to form a nonwoven web, fairly pronounced soiling appears on thefunctional surfaces for guiding or treating the nonwoven web due to theadherence of unbonded short fibers or dust particles. These types offunctional surfaces, which may be provided on laydown belts, transportbelts, calenders, or individual guide rollers, must therefore becontinuously or intermittently cleaned to ensure product quality. It isgenerally known to use rotating brush segments for cleaning thefunctional surfaces. Such a device is known from DE 197 26 970 A1, forexample.

In the known device for cleaning a functional surface, multiple hollowcylindrical brush segments are adjacently situated on a roller body. Thebrush segments are connected to one another in a positive-fit manner inthe axial direction and braced against one another at the ends of theroller body by attached adjusting rings. Thus, multiple brush segmentsmay be situated on a roller body, resulting in a brush roller.

SUMMARY

However, significant problems occur with the known device when it isused for cleaning a functional surface in an airlaid process. On the onehand, multiple brush segments for transmitting torque must be securelybraced at the periphery of the roller body by means of the adjustingrings. On the other hand, the harsh operating conditions, in particularfor use at fairly high surrounding temperatures, for example on acalender, result in differing expansions of the materials of the brushsegments and roller bodies which are combined with one another withinthe device. Conditions thus occur which cause the adjusting rings todrift apart during operation, resulting in loosening of the individualbrush segments.

It would be desirable to provide a generic device for cleaning afunctional surface for guiding or treating a material web, in which thebrush segments may be securely held at the periphery of the roller bodyunder all operating conditions.

It would further be desirable to provide a device for cleaning afunctional surface for guiding or treating a material web, in whichmultiple brush segments may be situated on a roller body in order toform a large working width.

Thus, embodiments are provided for a device in which at least one of theadjusting rings is mounted in an axially movable manner at the peripheryof the roller body, and a clamping ring which is connected to themovable adjusting ring in a rotationally fixed manner is axially bracedagainst the roller body by means of at least one spring element in sucha way that an axial tension force is generated which acts on the brushsegments.

Additional advantageous refinements are also provided.

Embodiments have the advantage that during operation, relative motionsbetween the roller body and the brush segments are possible due todiffering material expansions. Loss of the tension force generated onthe brush segments in the axial direction is thus avoided by means ofthe adjusting rings. Depending on the field of application, fairly highpretensioning may be produced for fixing the brush segments as afunction of the selection of the spring element. As a result of thespring element, the brush segments remain in their predefined locationat the periphery of the roller body.

To allow the largest possible working widths using an appropriateplurality of brush segments, in one embodiment, the roller body has oneof multiple spring-loaded clamping rings on both end faces, which areconnected in a rotationally fixed manner to the movably mountedadjusting rings and which generate axial tension forces which actoppositely on the roller body. Even fairly large relative motions maythus be compensated for in order to hold the brush segments fixed inposition at the periphery of the roller body.

Since the torque is to be transmitted solely via the axial bracingbetween the adjusting rings and the brush segments, some embodimentsoffer the particular advantage that multiple coupling sites may beachieved between the roller body and the clamping ring in order totransmit the torque from the roller body toward the adjusting rings andthe brush segments. Thus, the spring elements are formed by multipledisk spring assemblies or by multiple compression springs which areuniformly distributed at the end face of the roller body. The bracingand the connection of the clamping ring to the roller body are thusachieved by multiple fastening elements.

To achieve transmission of the torque between the roller body and theclamping ring with as little play as possible, in one embodiment, thefastening elements are designed as screws for the rotationally fixedfastening of the clamping ring to an end wall of the roller body, theclamping ring having multiple drill bushings for accommodating thescrews. Thus, high wear resistance during the transmission of torque isalso achieved.

The positive-fit connection between the brush segments and the adjustingrings as well as among the brush segments themselves may be establishedby toothing on each end face. The so-called Hirth serration has provento be particularly suitable.

Particularly large working widths may thus be achieved, so that,according to one embodiment, the brush segments at the periphery of theroller body are arranged together to form a brush width in the range of2000 mm to 4000 mm. Such brush widths are particularly suitable foruniformly cleaning the functional surface of laydown belts and calenderrollers over the entire working width in the manufacture of nonwovens.

For accommodating and driving the roller body, the roller body may havestub axles, projecting at each end face, which are mounted on a rollersupport. At least one of the stub axles may be directly coupled to adrive.

Depending on the application, and whether continuous or intermittentcleaning of the functional surface is desired, according to oneembodiment, the roller support may have a movable design, so that theroller body is guidable between an operating position and a neutralposition. This is particularly advantageous for the intermittentcleaning of functional surfaces.

To obtain high stability in the holding and guiding of the brushsegments over large working widths, the roller body may be formed by adouble-tube shell having an inner tube and an outer tube which areconnected to the stub axles at both end faces. A particularlylightweight design having high stability may be achieved in this way.

The brush segments may be accommodated at the periphery of the rollerbody by a holding sleeve which has a surface that is adapted to thecharacteristics of the brush segments, so that, for example, individualbrush segments may be quickly replaced.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below by means of severalexample embodiments of the device according to the invention, withreference to the accompanying figures, which show the following:

FIG. 1 schematically shows an example device for manufacturing anonwoven web, having multiple functional surfaces for guiding ortreating a nonwoven web.

FIG. 2 schematically shows a cross-sectional view of a first exampleembodiment of the device.

FIG. 3 schematically shows a cross-sectional view of another exampleembodiment of the device.

DETAILED DESCRIPTION

FIG. 1 illustrates an example device for manufacturing a nonwoven web asused in an airlaid process. Such a device has multiple functionalsurfaces, which, in each case, are cleaned by the device according tovarious embodiments. FIG. 1 shows only a small portion of the unit formanufacturing and treating the nonwoven web. Thus, a nonwoven web 2formed from short fiber pieces is produced on the functional surface ofa laydown belt 3. For this purpose, a forming station 1 which lays thefiber pieces on the laydown belt 3 is associated with the laydown belt3. A suction unit 4 on the underside of the laydown belt 3 is associatedwith the forming station 1. The laydown belt 3 is continuously driven,and is guided over the guide rollers 7. The surface of the laydown belt3 forms a functional surface 9 which is cleaned using the deviceaccording to various embodiments. In this regard, the cleaning device8.1 is shown. The cleaning device 8.1 has a roller support 11 on which aroller body 10 is guided. By use of the roller support 11, the rollerbody 10 may be guided into an operating position (as depicted in FIG. 1)and into a neutral position which is provided at a distance from thelaydown belt 3 (not depicted). In the operating position, the rollerbody 10 is mounted for cleaning the functional surface 9 of the laydownbelt 3.

The nonwoven web 2 is led to a calender station 5 for bonding of thenonwoven web. In the present example embodiment, the calender station 5is formed by two calender rollers 6.1 and 6.2, between which a rollernip is formed for guiding and treating the nonwoven web 2. At the sidesopposite from the roller nip, cleaning devices 8.2 and 8.3, according tovarious embodiments, are associated with the calender rollers 6.1 and6.2, respectively. In this case, the functional surfaces 9 are formed atthe periphery of the calender rollers 6.1 and 6.2, and are continuouslycleaned by the cleaning devices 8.2 and 8.3.

The cleaning devices 8.1 through 8.3 illustrated in FIG. 1 have anessentially identical design, which is explained below with reference toseveral specific example embodiments. FIG. 2 schematically illustrates afirst example embodiment of the device in a cross-sectional view, aswould be usable, for example, as a cleaning device 8.1, 8.2, or 8.3.

The device illustrated in FIG. 2 has a roller body 10 which has a hollowcylindrical design, and which at each end is fixedly connected to a stubaxle 12.1 and 12.2, respectively. The ends of the stub axles 12.1 and12.2, which are not illustrated here in greater detail, are used for therotatable bearing of the roller body 10 on a roller support, and fortransmitting a torque which is generated by a drive which is coupled toat least one of the stub axles 12.1 and 12.2. One of the stub axles 12.1and 12.2 is therefore connected to a drive, not illustrated here.

A cylindrical holding sleeve 15 is attached at the periphery of theroller body 10. Multiple hollow cylindrical brush segments 13 aremounted at the periphery of the holding sleeve 15. The brush segments 13have an identical design, and include a circular brush 28 and a brushholder 29. The brush holders 29 each have end-face toothing 16 at theirend faces. The toothings 16 of the brush holders 29 intermesh, so that apositive-fit connection is present between the brush segments 13.

A first adjusting ring 14.1 is situated at the periphery of the holdingsleeve 15 at the left end of the roller body. The adjusting ring 14.1 isfixedly connected to the roller body 10 via a fixing means 17. Theadjusting ring 14.1 likewise has toothing 16 on the end face facing thebrush segment 13 which establishes a positive-fit connection to theadjacent brush segment 13.

An axially movable adjusting ring 14.2 is situated at the opposite endof the holding sleeve 15. The adjusting ring 14.2 has toothing 16 on itsend face facing the brush segment 13 which connects the adjusting ring14.2 to the brush segments 13 in a positive-fit manner. A clamping ring19 is situated at the opposite end of the adjusting ring 14.2. Theadjusting ring 14.2 is connected to the clamping ring 19 situated at theend face of the roller body 10. For this purpose, via a shoulder theclamping ring 19 is fixedly connected directly to the adjusting ring14.2 by multiple joining means 18. The clamping ring 19 is axiallyadjustably held against an end wall 30 of the roller body 10 viamultiple fastening elements 23. A spring element 20 is clamped betweenthe fastening element 23 and the clamping ring 19, so that the clampingring is pushed in the direction of the brush segments 13 as the resultof an axially directed elastic force. In the present example embodiment,the fastening elements 23 are formed by multiple screws which areuniformly distributed at the end wall 30 of the roller body 10. Thespring elements 20 are formed by multiple compression springs 22 which,in each case, are clamped between a head of the screw 23 and a shoulderof the clamping ring 19. As a result of the compression springs 22,which are uniformly distributed at the face of the clamping ring 19, anaxial tension force is generated which acts on the adjusting ring 14.2via the clamping ring 19, and which thus braces the entire brushassembly of brush segments 13 against the opposite adjusting ring 14.1.

In the operating state, the roller body 10 is driven by the stub axles12.1 and 12.2. The torque is transmitted toward the adjusting rings 14.1and 14.2 at both end faces of the roller body 10, so that the entireassembly of brush segments 13 is rotationally driven.

The transmission of torque to the adjusting ring 14.1 is ensured by thefixing means 17. On the opposite side, the torque is transmitted to theadjusting ring 14.2 by the clamping ring 19 and the screws 23.

To allow cleaning of the largest possible working widths, preferablyusing a roller body and brush segments fastened thereto, thepretensioning produced by spring elements for fixing the brush segmentsis preferably provided at both end faces of the roller body 10. In thisregard, FIG. 3 schematically shows one example embodiment of the deviceaccording to the invention in a cross-sectional view. The exampleembodiment according to FIG. 3 has a double-tube shell 25 as a rollerbody 10 which is formed by an inner tube 26 and an outer tube 27 whichencloses the inner tube 26 at a distance therefrom, the inner tube andthe outer tube being connected at their free ends to the stub axles 12.1and 12.2. A holding sleeve on which the brush segments 13 are mounted issituated at the periphery of the double-tube shell 25. The brushsegments 13 have a design which is identical to the preceding exampleembodiment, so that no further explanation in this regard is providedhere.

For axially bracing the brush segments 13, axially movable adjustingrings 14.1 and 14.2 are respectively situated at each end of the rollerbody 10. A clamping ring 19.1 and 19.2 is associated with each of theadjusting rings 14.1 and 14.2, respectively. The clamping ring 19.1 iscoupled to the adjusting ring 14.1 in a rotationally fixed manner via ashoulder. For this purpose, multiple joining means 18 are distributed atthe periphery of the clamping ring and fixedly connected to theadjusting ring 14.1.

The oppositely situated clamping ring 19.2 is coupled to the adjustingring 14.2 in the same way.

For the axial bracing, in the present example embodiment the springelements are formed by multiple disk spring assemblies 21 which are heldvia multiple screws 23 for axially bracing the clamping ring 19.1. Thescrews 23 are screwed into the end wall 30.1 of the roller body 10, thedisk spring assemblies 21 being tensioned in each case between a head ofthe screw 23 and a shoulder of the clamping ring 19.1.

A drill bushing 24 passes through the clamping ring 19.1, concentricallywith respect to the disk spring assemblies 21, for accommodating thescrew 23. A drill bushing 24 in the clamping ring 19.1 is thusassociated with each screw 23. Thus, an essentially play-free connectionfor transmitting torque may be established between the roller body 10and the clamping ring 19.1.

The clamping ring 19.2 is likewise coupled to the opposite end wall 30.2via multiple screws 23 and drill bushings 24. A disk spring assembly 21is likewise associated with each of the screws 23, so that an axiallyacting pretensioning force likewise results at the clamping ring 19.2due to the disk spring assemblies 21.

As a result of the clamping rings 19.1 and 19.2, the oppositely actingaxial tension force is introduced at the adjusting rings 14.1 and 14.2,respectively, which brace the brush segments 13 at the periphery of theholding sleeve 15. It is important that relatively high torques aretransmittable to the brush segments 13 due to the connection of theclamping rings 19.1 and 19.2 by multiple uniformly distributed fasteningelements 23. In this regard, the example embodiment according to FIG. 3is particularly suited for removing especially stubborn soiling on thefunctional surfaces.

The example embodiments of the device according to the inventionillustrated in FIGS. 2 and 3 are particularly suited for continuously orintermittently cleaning the functional surfaces illustrated in FIG. 1.The characteristics of the brush segments, in particular of the circularbrushes, are individually selectable, depending on the type of soilingor the type of functional surfaces that are present. Thus, such devicesmay even be used for cleaning screen cloth strips in dryers, where thesurrounding temperature is approximately 90° C., and the brush segmentsare held in continuous linear contact with a screen cloth strip surfacehaving a surface temperature of 200° C. Similar conditions are alsopresent during cleaning of the functional surfaces on calender rollers,which typically have a surface temperature of above 100° C. Self-heatingof the roller body has no effect on the bracing and torque transmissionof the individual brush segments.

While various embodiments of the invention have been particularly shownand described, it will be understood by those skilled in the art thatvarious changes in form and details may be made therein withoutdeparting from the spirit and scope of the invention as defined by theappended claims.

It should be understood that all embodiments which have been describedmay be combined in all possible combinations with each other, except tothe extent that such combinations have been explicitly excluded.

Finally, nothing in this Specification shall be construed as anadmission of any sort. Even if a technique, method, apparatus, or otherconcept is specifically labeled as “prior art” or as “conventional,”Applicant makes no admission that such technique, method, apparatus, orother concept is actually prior art under 35 U.S.C. §102, suchdetermination being a legal determination that depends upon manyfactors, not all of which are known to Applicant at this time.

LIST OF REFERENCE NUMERALS

-   1 Forming station-   2 Nonwoven web-   3 Laydown belt-   4 Suction unit-   5 Calender station-   6.1, 6.2 Calender rollers-   7 Guide rollers-   8.1, 8.2, 8.3 Cleaning device-   9 Functional surface-   10 Roller body-   11 Roller support-   12.1, 12.2 Stub axle-   13 Brush segments-   14.1, 14.2 Adjusting ring-   15 Holding sleeve-   16 Toothing-   17 Fixing means-   18 Joining means-   19, 19.1, 19.2 Clamping ring-   20 Spring element-   21 Disk spring assembly-   22 Compression spring-   23 Fastening element, screw-   24 Drill bushing-   25 Double-tube shell-   26 Inner tube-   27 Outer tube-   28 Circular brush-   29 Brush holder-   30.1, 30.2 End wall

1. A device for cleaning a functional surface for processing a materialweb, the device comprising a rotatably supported roller body which hasmultiple hollow cylindrical brush segments at its periphery, the brushsegments being connected to one another in a positive-fit manner, andthe brush segments being tensioned between two adjusting rings situatedat the periphery of the roller body, wherein: at least one of theadjusting rings is mounted in an axially movable manner at the peripheryof the roller body; and a clamping ring that is connected to the atleast one axially movable adjusting ring in a rotationally fixed manneris axially braced against the roller body with at least one springelement in such a way that an axial tension force is generated whichacts on the brush segments.
 2. The device according to claim 1, wherein:the roller body has two axially-opposite end faces; the clamping ring isaxially braced against a first end face of the two end faces of theroller body; another clamping ring is axially braced against a secondend face of the two end faces of the roller body, the other clampingring being connected in a rotationally fixed manner to another movablymounted adjusting ring, the clamping ring and the other clamping ringgenerating axial tension forces which act oppositely on the roller body.3. The device according to claim 1, wherein: the spring element isformed by multiple compression springs which are uniformly distributedat the end face of the roller body.
 4. The device according to claim 1,wherein: the spring element is formed by multiple disk spring assemblieswhich are uniformly distributed at the end face of the roller body. 5.The device according to claim 4, wherein: the disk spring assemblies areclamped between one of multiple fastening elements and the clampingring.
 6. The device according to claim 5, wherein: the fasteningelements are screws for the rotationally fixed fastening of the clampingring to an end wall of the roller body, the clamping ring havingmultiple drill bushings for accommodating the screws.
 7. The deviceaccording to claim 1, wherein: the adjusting rings and the brushsegments are connected to one another in a positive-fit manner at theperiphery of the roller body by end-face toothing in each case.
 8. Thedevice according to claim 1, wherein: the brush segments are connectedto one another at the periphery of the roller body by end-face toothing.9. The device according to claim 8, wherein: the brush segments at theperiphery of the roller body are arranged together to form a brush widthin the range of 2000 mm to 4000 mm.
 10. The device according to claim 1,wherein: the roller body has two axially-opposite end faces; foraccommodation on a roller support, the roller body has stub axlesprojecting at each end face, one of the stub axles being coupled to adrive.
 11. The device according to claim 10, wherein: the roller supporthas a movable design, the roller body being guidable between anoperating position and a neutral position.
 12. The device according toclaim 10, wherein: the roller body is formed by a double-tube shellhaving an inner tube and an outer tube which are connected to the stubaxles at both end faces.
 13. The device according to claim 12, wherein:a holding sleeve is attached at the periphery of the double-tube shell,the brush segments being mounted so as to be pushable onto the holdingsleeve.